scholarly journals The Effect of an External Magnetic Field on the Aspect Ratio and Heat Input of Gas-Metal-Arc-Welded AZ31B Alloy Weld Joints Using a Response Surface Methodology

Materials ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5269
Author(s):  
Pankaj Sharma ◽  
Somnath Chattopadhyaya ◽  
Nirmal Kumar Singh ◽  
Marta Bogdan-Chudy ◽  
Grzegorz Krolczyk

This study attempted to analyze and optimize the effect of an external magnetic field (EMF) on the aspect ratio and heat input for AZ31B weld joints that were welded using the gas metal arc welding (GMAW) process. The response surface methodology (RSM) was adopted for the critical analysis, and subsequently, mathematical models were developed based on the experimental results. It was observed that the EMF and its interaction with the wire feed rate significantly affected the aspect ratio and heat input, respectively. At 119 G (magnetic field), 700 mm/min (welding speed), 5.8 m/min feed rate, and 11.5 L/min (gas flow rate), the aspect ratio was 2.26, and the corresponding heat input factor (HIf) was 0.8 with almost full weld penetration.

2021 ◽  
Vol 406 ◽  
pp. 319-333
Author(s):  
Tahar Saadi ◽  
Mohamed Farid Benlamnouar ◽  
Nabil Bensaid ◽  
Amar Boutaghane ◽  
Mohamed Amine Soualili ◽  
...  

The present study, aims to investigate, under welding parameters of current, voltage and gas flow, the effects of welding parameters on tensile strength of AISI 304L ASS welds using response surface methodology (RSM). The RSM and variance analysis (ANOVA) were used to check the validity of quadratic regression model and to determine the significant parameter affecting tensile strength of welds. Hence, ANOVA clearly revealed that the contribution of each factor is 71.40% of voltage, 19.2% of current and 8.30% of gas flow. It was found that combined contributions of welding parameters contributes significantly to the metallurgical changes by varying fractions, morphology and grain size of metallic compounds. Furthermore, the optimum automatic welding conditions lead to produce the best possible weld quality in the range of our experiment using desirability function approach for single response of RSM optimization factors, in which it concluded that tensile strength components are influenced principally by voltage. Finally, the ranges for best welding conditions are proposed for serial industrial production.


Author(s):  
Benjamin E. Rimai ◽  
Raymond J. Cipra

The use of micro-pin feeder-bowls has been established as a way to singulate and orient micro-scale metallic pins of varying lengths. Increasing the rate and reliability with which pins can feed through the bowl is important when considering the use of such a feeder-bowl in an industrial setting. Previous experimental work, which was limited to a single driving frequency and small range of driving amplitudes of the feeder-bowl, showed low feed rates and long capture times for pins whose aspect ratio exceeded five-to-one. New experimental work has shown that by altering the driving amplitude and frequency of the feeder-bowl, pins with aspect ratios exceeding seven-to-one could be fed. Because the frequency response of feeder-bowls may be limited, other techniques for improving the feed rate for long pins were also sought. One such technique was the magnetizing of the pins to increase their response to a magnetic field which surrounded the feeder-bowl. In some circumstances, more than a 70% reduction in average capture time was observed. The improved capture performance for long pins will permit more freedom in the design of devices that can be assembled with the aid of vibratory micro-pin feeder-bowls. The research results will also be used to improve the accuracy of feeder bowl simulations.


2013 ◽  
Vol 779 ◽  
pp. 14-21 ◽  
Author(s):  
M. Reza Hormozi-Nezhad ◽  
Hossein Robatjazi ◽  
Mehdi Jalali-Heravi

Author(s):  
Neelesh Ku. Sahu ◽  
A. B. Andhare

Surface roughness is an important surface integrity parameter for difficult to cut alloys such as Titanium alloys (Ti-6Al-4V). In the present work, initially a mathematical model is developed for predicting surface roughness for turning operation using Response Surface Methodology (RSM). Later, a recently developed advanced optimization algorithm named as Teaching Learning Based Optimization (TLBO) is used for further parameter optimization of the equation developed using RSM. The design of experiments was performed using central composite design (CCD). Analysis of variance (ANOVA) demonstrated the significant and non-significant parameters as well as validity of predicted model. RSM describes the effect of main and mixed (interaction) variables on the surface roughness of titanium alloys. RSM analysis over experimental results showed that surface roughness decreased as cutting speed increased whereas it increased with increase in feed rate. Depth of cut had no effect on surface roughness. By comparing the predicted and measured values of surface roughness the maximum error was found to be 7.447 %. It indicates that the developed model can be effectively used to predict the surface roughness. Further optimization of the roughness equation was carried out by TLBO method. It gave minimum surface roughness as 0.3120 μm at the cutting speed of 1704 RPM (171.217 m/min), feed rate of 55.6 mm/min (.033 mm/rev) and depth of cut of 0.7 mm. These results were confirmed by confirmation experiment and were better than that of RSM.


2016 ◽  
Vol 16 (2) ◽  
pp. 75-88 ◽  
Author(s):  
Munish Kumar Gupta ◽  
P. K. Sood ◽  
Vishal S. Sharma

AbstractIn the present work, an attempt has been made to establish the accurate surface roughness (Ra, Rq and Rz) prediction model using response surface methodology with Box–Cox transformation in turning of Titanium (Grade-II) under minimum quantity lubrication (MQL) conditions. This surface roughness model has been developed in terms of machining parameters such as cutting speed, feed rate and approach angle. Firstly, some experiments are designed and conducted to determine the optimal MQL parameters of lubricant flow rate, input pressure and compressed air flow rate. After analyzing the MQL parameter, the final experiments are performed with cubic boron nitride (CBN) tool to optimize the machining parameters for surface roughness values i. e., Ra, Rq and Rz using desirability analysis. The outcomes demonstrate that the feed rate is the most influencing factor in the surface roughness values as compared to cutting speed and approach angle. The predicted results are fairly close to experimental values and hence, the developed models using Box-Cox transformation can be used for prediction satisfactorily.


2015 ◽  
Vol 1119 ◽  
pp. 622-627 ◽  
Author(s):  
Chye Lih Tan ◽  
Azwan Iskandar Azmi ◽  
Noorhafiza Muhammad

Drilling is an essential secondary process for near net-shape of hybrid composite as to achieve the required dimensional tolerances prior to final application. Dimensional tolerance is often influenced by the surface integrity or surface roughness of the workpart. Thus, this paper aims to employ the Taguchi and response surface methodologies in minimizing the surface roughness of drilled carbon-glass hybrid fibre reinforced polymer (CGCG) using tungsten carbide, K20 drill bits. The effects of spindle speed, feed rate and tool geometry on surface roughness were evaluated and optimum cutting conditions for minimizing the aforementioned response was determined. Subsequently, response surface methodology (RSM) was utilised in finding the empirical relationships between experimental parameters and surface roughness based on the Taguchi results. The experimental analyses reveal that surface roughness is greatly influenced by feed rate and tool geometry rather than the spindle speed. This is due to the increment of feed that attributed to the increased strain rate and hence, deteriorated the surface roughness of the hybrid composite. The predicted results (via regression model) and theoretical results (via additivity law) were in good agreement with experiment results. This indicates that the regression model from response surface methodology (RSM) can be used to predict the surface roughness in machining of CGCG hybrid composite.


Doklady BGUIR ◽  
2021 ◽  
Vol 19 (2) ◽  
pp. 5-13
Author(s):  
V. M. Fedosyuk

 The results of study of the giant magnetoresistance coefficient (GMR) in multilayer micro- and nanowires based on successively alternating ferromagnetic (Co, CoNi and NiFe) and diamagnetic (Cu) layers are presented in the paper. The samples were obtained by electrochemical deposition into the matrix pores. Aluminum oxide was used as matrices. To establish the influence of the aspect ratio, matrices of two types were used: with a pore diameter of 8 µm and 170–200 nm and a variable thickness from 10 to 60 µm. Investigations of the GMR coefficient were carried out by measuring the current-voltage characteristics in external magnetic fields up to 130 mT. When using type I matrices (pore diameter 8 μm), a positive GMR coefficient (an increase in electrical resistivity in an external magnetic field) was noted, while when using type II matrices (pore diameter 170–200 nm), a negative GMR coefficient was established (a decrease in electrical resistance in an external magnetic field). This is due to the enhancement of the interactions of spin-polarized electrons in the magnetic layers through the copper layer through the RKKY exchange with an increase in the aspect ratio. A significant effect of the composition of the ferromagnetic layer (Co, CoNi, and NiFe) on the value  of the GMR coefficient is noted. The maximum value of the negative GMR coefficient (up to –27.5 %) was established for the CoNi-based nanowire system. The use of multilayer micro- and nanowires, electrolytically deposited in a matrix of aluminum oxide with the ability to control the GMR coefficients, opens up perspective use of these objects as sensitive elements (sensors) of a constant magnetic field, as well as devices for storing magnetic information with a vertical principle. 


2019 ◽  
Vol 9 (24) ◽  
pp. 5330 ◽  
Author(s):  
Ángel de la Rosa ◽  
Gonzalo Ruiz ◽  
Elisa Poveda

The compression behavior of steel-fiber reinforced concrete (SFRC) has been addressed exhaustively in recent decades thereby highlighting a variety of differences with regard to the effect that the addition of fiber has on it. In this paper, a detailed study of the subject is developed for which a database has been created, which includes 197 tests performed on cylindrical concrete specimens with dimensions of 150 × 300 mm 2 (diameter × height). By means of the response surface methodology, we disclose the relationship that exists between the geometric parameters of the fiber (length, diameter, and aspect ratio), their amount (fraction in volume), and some matrix parameters (compression resistance and maximum size of coarse aggregate) with the different compression responses of the SFRC, which are strength, elastic modulus, critical deformation under maximum load, and the volumetric deformation work in the pre- and post-peak branch. Linear polynomial models are chosen to adjust each response with the defined factors, and said variables are studied in a dimensional and non-dimensional format. From the results obtained, it is verified how the inclusion of steel-fibers produces notable improvements in ductility and the energy absorption capacity of the concrete when significantly increasing the works of volumetric deformation in the pre- and post-peak branch with respect to the matrix without fibers. In addition, a new model is analyzed, which describes the stress–strain curve of the compression behavior of the SFRC based on the increase of ductility and energy absorption. This model is characterized by a softening branch subsequent to the peak load determined by means of the residual compressive strength, a parameter that corresponds to the value of the compressive stress associated with a strain equal to three times that of the peak of the curve, which is significantly dependent on the aspect ratio and fiber content.


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